Wooden culvert



Patented Mar. 2, 1943 UNlTED STATES PATENT GFFECE WOODEN CULVERT Henry E.Kuphal, Sacramento, Calif.

Application June 15, 1942, Serial No. 447,074

(Cl. 13S-79) 7 Claims.

This invention relates in general to an improved culvert or similar conduit structure, and in particular the invention is directed to an allwood culvert, prefabricated from a plurality of straight boards, a major portion of which are identical size and conguration, and all of which are arranged in unique interlocking relation, whereby to produce an assembly which is rigid, self-sustaining and easy to manufacture.

The culvert, in essence, comprises a plurality of equal sided open-ended polygonal sections (here shown as square), disposed in axial alinement and end to end engagement; alternate ones of said sections being turned about the axis thereof a predetermined and equal extent so `that the corners of said alternate sections project some distance beyond corresponding sides of adjacent sections centrally between the ends of the latter, and there being longitudinal splines or keys extending through corresponding ones of said projecting corners and frictionally engaging between the same and the outer surface of the adjacent sides of said sections whereby to frictionally maintain the parts at the desired interlocking relationship.

It is also an object of the present invention to provide a culvert prefabricated from wooden parts, which may be constructed-with slight variation in said parts-s0 that the inside of the culvert presents either an unbroken or an intermittently broken surface to produce a smooth or turbulent ow respectively.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following j specification and claims.

In the drawing similar characters of reference indicate corresponding parts in theseveral views:

Figure 1 is a perspective view of my improved al1-wood culvert.

Figure 2 is an end view of the same.

Figure 3 is a perspective view of one side, detached, of a section.

Figure 4 is a plan view of one side, detached, of a section as notched to provide an unbroken or smooth interior surface in the culvert.

Referring now more particularly to the characters of reference on the drawing, the culvert, as shown in the present embodiment, comprises a plurality of open-ended sections, square in end plan, indicated generally at l, disposed 1n end to end engagement and in axial alinement; each of said sections comprising four sides 2 of like dimensions, said sides being Wooden planks of substantial width and thickness, as shown. At adjacent ends the sides 2 may be half notched, as at 3, in opposed relation and then symmetrically engaged so that a portion of each end abuts directly against a portion of the other end.

The sections I, as previously indicated, engage each other in end to end relation but alternate ones of said sections, as for example the sections indicated at 4, are turned about their axis to such extent (45 in the present embodiment) that the corners 5 of said alternate sections 4 project outwardly beyond the outer surface of the sides 2 of the adjacent sections.

The sides 2 of adjacent sections are cooperatively notched as at 6 at the point of intersection and the depth of these notches controls the extent of overlap of one section relative to the other.

It will be seen that if the notches 6 are of a depth equal to one-quarter the width of sides 2, as shown in Fig. 4, the adjacent edges of alternate sections will be in full end to end engagement, whereby the interior of the culvert will then present a smooth surface for smooth flow. However, if the notches 6 are not of such a depth, as shown in Figs. 1 and 3, the adjacent ends of alternate sections will not be in engagement and the interior of the culvert will not have an unbroken surface, and the flow therethrough will, as a result, be turbulent, and as is desired under certain conditions. l

Interlocking of the sections of the culvert is completed by at longitudinal splines or key l which extend through corresponding longitudinally alned corners 5 in close frictional engagement between the latter and the outer surface of adjacent sides 2; said splines being tapered along opposite edges, as at 8, in matching relation to the angle of the inner surface of corners 5. The longitudinal keys 1 extend the full length of the conduit, and, as will be seen, completely interlock the sections and maintain the assembly in rigid relation. No securing elements are needed with the sections, although ii desired dowels 9 may be used to secure the ends of said keys with the endmost ones of the sections l.

In assembling or erecting a culvert, the necessary number of keys 1 are irst set up and generally held in position with the aid of any suitable temporary frame or jig, and the sections are then successively slid along the keys and into the desired cooperative and interlocking relationship. When so doing, the keys 1 of any section may be sprung in slightly, if necessary, to facilitate sliding the sections in place.

It may be here noted that the notching 3 is mainly useful for assembling purposes and to facilitate handling or transportation of the sections, and such notching is not necessary to resist collapsing pressure from the outside. Such resistance to exterior pressure is taken care of by the fact that members 2 of one section press against the keys, which in turn press on the members of adjacent sections in a direction to counteract the pressure exerted against the first named members.

The culvert constructed as above is rigid and self-sustaining, and is capable of easy manufacture due to the fact that the sidesV 2 are each of like configuration, while the splines or keys 1 are of simple form readily milled. There are no parts in the structure requiring complexrnilling, steam-bending or like operations.

While this invention in its present embodiment employs sections which are square in end plan, it is obvious that sections having a greater number of sides may be employed, and secured together in substantially the same interlocking manner,l as hereinbefore described. Further, while designed for use as a culvert, they assembly may be used for such other purposes as may be found desirable.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what I Claim as new and useful and desire toY Secure by Letters Patent is:

1. A conduit comprising a plurality of initially separate open-ended sections. of like polygonal configuration in end plan, said sections being disposed in end to end engagement with the corners of each section projecting beyondV the sides of an adjacent section, and full length longitudinal keys extending through corresponding ones of said corners in engagement with but outwardly of said sides and holding the sections in assembled relation to each other.

2. A conduit comprising a plurality of initially separate open ended sections of like polygonal configuration in end plan, said sections being disposed in end to end engagement with the corners of each section projecting beyond the sides of an adjacent section, and full length longitudinal keys extending through corresponding ones of said corners in close frictional engagement between said corners and the outer surface of said sides, whereby to hold the sections in assembled relation to each other.

3. A conduit as in claim 2 in which the longitudinal keys are beveled along opposite longitudinal edges to matchingly engage within said corners.

4. A conduit comprising a plurality of initially Vseparate open ended sections of like polygonal configuration in end plan, said sections being disposed in end to end engagement with the corners of each section projecting beyond the sides of an adjacent section, the sides of the sections at the points of intersection being notched and the notches cooperatively engaged, and full length longitudinal keys extending through corresponding ones of said corners in close frictional engagement between said corners and said sides.

5. A conduit as in claim 1 in which the sections each comprising a plurality of straight sides of substantial width and thickness; said sides at adjacent ends being half-notched from opposite edges, and being symmetrically engaged, whereby each of said ends rests partially in abutting relation to the adjacent end; the longitudinal keys being frictionally engaged between said corners and the sides intermediate said ends.

6. A conduit comprising a plurality of initially separate open ended sections square in end and disposed in end to end engagement, alternate sections being turned 45 relative to adjacent sections whereby the corners of said alternate sections project beyond the sides of said adjacent sections centrally between the ends of said sides, and full length longitudinal keys extending through corresponding ones of said projecting corners in frictional engagement between the latter and said sides whereby to maintain said sections in assembled relation to each other.

'7. A conduit as in claim 2 in which the sides of the sections are of like configuration and interchangeable; said sides being initially separate and adjacent ends thereof being formed for end engagement with each other whereby the keys hold the sides of each section in assembled relatiOIl. and the sections normally against axial separation.

HENRY E. KU'PHAL. 

